An apparatus for feeding a fastener, especially a fastener which is elongated such as a stud or the like, to a fastening tool such as the welding head in a stud welder is known. The fasteners are forced individually through a first passage in the apparatus and into a holding means such as a chuck or the like by a plunger in another, second passage.
This apparatus is described for example in U.S. Pat. No. 3,339,799.
In this known apparatus the stud is fed through a first passage which opens into a second passage at an acute angle and, as soon as the stud has passed the opening into the second passage, is conveyed into a chuck or the like by a conveying member. The plunger is guided in another passage which is substantially aligned with and coaxial to the chuck.
It has been found to be a disadvantage, particularly with a very short stud or with a stud which has a head which is comparatively large in diameter and a shaft which is comparatively thin, that the stud can be oriented transversely in the vicinity of the opening of the first passage into the second passage so that the passage can become blocked by a jammed stud and the feeding of other studs to the chuck by the plunger is prevented.
Advantageously in the above-described apparatus, the plunger need only be axially slidable. Pivoting of the plunger is not required for feeding a stud.
In another stud welding unit, e.g. as described in German Patent No. 34 08 930, only one passage is provided in which a pivotable plunger or detent is engagable and axially slidable. This plunger or detent however must be pivoted out from the passage to allow the stud to pass. After that occurs the plunger is swung back into the passage to convey the stud by axial sliding into the holding means, especially a chuck. The kinematics of this type of stud welder is even more complicated than the stud welder first described above.